* changes:
libexpr: Rework error messages on ExprSelct::eval
libexpr: Track position information in attrpaths
libexpr: Assert: Don't print assertion in error message
libexpr: Split ExprAttrs and ExprLet
Calls to `show` have been removed. To counter the loss of information,
the error positions have been improved and now correctly point to the
current selector instead of the entire select expression.
Change-Id: I4771fe874af1ac15828a9863550cd4369a8f0e94
This is a pretty small change because the parser already has all
necessary information (needed for parse errors), now we want to keep it
to also provide better eval errors.
Change-Id: Ifc7a9516b9b0c8d9698f1899a6912ae91f6696ab
The `show` functionality needs to be removed because it is deeply
flawed, and given that we already print position information in the
error message (which probably wasn't always the case in the past) the
assertion printing is redundant anyways.
Change-Id: I1f5e05ab73aaa0ec92994c2211463260fd374898
ExprLet was previously inheriting from ExprAttrs for the data, while
ignoring all
set-specific operations on it. The set specific code has now been split
off so that
let doesn't inherit it anymore:
- ExprAttrs (not an Expr), containing the attributes and the related
logic
- ExprLet : Expr, ExprAttrs
- ExprSet : Expr, ExprAttrs
Co-authored-by: eldritch horrors <pennae@lix.systems>
Change-Id: I63f2fbcd1e790b3cffb56eec1e7565ee3cdbf964
these must be tampered with before the evaluator is created, *never*
after. doing it any other way leads to interesting things like #596.
fixes#596
Change-Id: Iea253ccce44b94b1243833837a3df93c795967d9
Calling a custom type size_t is incredibly sneaky and makes all the code
around this extremely context dependent.
Change-Id: Idae684781f45fe615020d8642f12a656ab2c15ad
this finally gives us a witness type we can use to prove that a certain
call graph subtree can't be used in kj promises using only a single new
assumption: if EvalState& is never held as a reference member of a type
and instead only ever passes as an argument or held on the stack we can
be certain that anything that has access to en EvalState ref must never
be run inside a promise and, crucially, that anything that doesn't have
access to an EvalState& *can* be run inside a promise without problems.
Change-Id: I6c15ada479175ad7e6cd3e4a729a5586b3ba30d6
"persistent" here means state that outlives any particular evaluation,
i.e. everything that exist outside of a call to eval() and friends. do
note that this leave EvalState nearly empty, containing only things of
importance to evaluation *itself*, e.g. the call depth tracker. do not
worry about the self-reference ctx member. nothing to see here, go on.
Change-Id: Ie8d0af3f09d33902f81e0c36a1096dd9f334a537
for the same reason the eval caches should not keep them as references,
only worse: installables cannot fully lose their reference member since
some types of installable (flakes -sigh-) need access to caches held by
their member reference. passing that around as well at all times is not
feasible; passing in EvalState& all the time is quite bad enough as is.
Change-Id: I05d438623b5ef10fc22e7e256b89447e61a0657d
this is not necessary in any way, but it will make the following changes
smaller and easier to review. the aliases could also be added piecemeal,
but doing it here lets us lean heavily on our compilers for correctness.
(teacher notes: here the author foreshadows the shape of things to come.
not all names change, and only the names unchanged are those which will,
over time, become ever more unrecognizable. note especially nix/main.cc,
where `state` is not only cloned, but itself changes pointerness. it can
be seen as a nod to the trans community, but more realistically it is no
more than foreshadowing the future where `state` is only seen by proxy.)
Change-Id: I7732025e58df089b7f8e564fc63960cd91729d09
it's not used for anything any more. it was only passed on to the AttrDb
constructor, which itself only stashed it away to an unused member field
Change-Id: I334fde751a3754e6580f573c21ae3d04be00345a
and for the same reason DrvInfo shouldn't, only even more so. the eval
cache infrastructure wants to be a wrapper around evaluation, with its
lifetimes fully decoupled from the lifetime of the wrapped evaluation.
this can't not create problems when eval lifetime must become bounded.
Change-Id: Ib8eec649995b4decd7290c2266322f67d73b6b46
in the future eval states will be asyncio root contexts. proving that
they are used correctly is impossible if the are referenced by things
with weakly scoped lifetimes, or entirely unscoped lifetimes, as we'd
have to deal with in the case of `DrvInfos` passed as out parameters.
Change-Id: I9ca5c46a714c6c914a77c7c7500cb4939ac9aff5
it's all strings anyway. the db stores strings, the cli wants to
interact with attr paths as strings, so we will just use strings
Change-Id: Id9ea07d92343de77e8d47af8fec1e86ae225e9a1
there's no reason for these to be private. much more important things
that are now part of EvalState are not private, and having statistics
be private forces us to add otherwise unnecessary friend declarations
Change-Id: Ib37097d94a9f55c2b21969fb6c51049b1c914515
thunk creation doesn't have to be called that. thunks are more of an
implementation detail, calling it evalLazily seems a lot more clear.
Change-Id: I64bdac422eadb629002195cd6b6a89dce1b4a60f
this will let us pass the capability to create debuggable eval errors
without having to pass an entire EvalState. we could pass symbols and
debug states around just as easily, but if we add new capabilities to
our debugger we might have to change many more places than with this.
Change-Id: I2f8893012e5d98a986ef1fc888234c2dd8d5e096
if we hold the error being built behind a pointer we no longer need to
allocate the error builder itself to avoid impacting eval performance.
adding && ref qualifiers to builder functions and adding the nodiscard
attribute to the class itself also makes the nodiscard attributes kept
on the builder functions unnecessary. we do keep the noinlines though,
removing them still regresses eval performance even after this change.
Change-Id: Ibc14a66955ac32142d97fb3680b0a7e14db250cd
this is necessary to share a debug state between multiple eval states.
while doings so makes little sense at present it will be necessary for
async io support since eval states must be async io roots, which means
we must create them as needed from a shared evaluation context object.
Change-Id: Id9d4b37aae40706f65c741e3b961855582e035ab
if we define a TraceableAllocator at all times and use that in places
that want maybe-traceable allocation we can simplify things a lot. we
also unconditionally allocate cache root pointers for Value and Env-1
caches, even though we don't need them without gc (they're so cheap).
defaulting to `std::allocator` without gc recovers previous behavior.
Change-Id: I236da8c3b0669b40cdfe355ec3ec4e764d096074
that way we don't need to eval while initializing the evaluator. this
will make a lot more sense once we start pushing asyncio through here
Change-Id: I3663052438ed97d48e213b71395ad1dd5e1318bb
currently only used to hide the nix code of derivation from stack traces
and debug frames, but perhaps we'll find it useful for other things too.
Change-Id: Ie5667873d8858d25dd4113bdf454e800b59082d7
this doesn't belong here, getFlake should be handling this instead. we
do lose the debug frame for loading a root flake, but that seems fine.
there's no point in starting a debugger if the root isn't even a flake
Change-Id: I24ad32b6716baee81a1a0f8bf9ce26814d97c7aa
this was only used to enable an optimization we no longer need such
strong guarantees for: SmallVector can be used with a dynamic size.
Change-Id: I4513fb7e665827fe363ce6308448656e6c5badb7
Error::addTrace exists and is used far more often already. let's
standardize on the variant that doesn't need yet more templates.
Change-Id: If66b69ca02dbb546ce98cf385181bd13ce7ad9b5
the callback is always called immediately, which defeats the purpose of
the callback and the purpose of the template itself. there seems to not
be any performance impact of this. optimizing Value::determinePos would
be nice, but it's not used nearly often enough to matter at this point.
Change-Id: I2aec6a38103630652112f4b273653f11d2404c04
nothing needs these any more. the CLI calls evalFile, but only in places
where it'll only be called *once* per process lifetime. __import does so
too, but import doesn't care about the parse tree, only the eval result.
interestingly this improves eval performance by 6% on system eval unless
GC never occurs. no idea why this makes a GCing eval faster, but it does
Change-Id: I8289528550244e0a8b5ebc7284d8fb9aaac59e20
only generate-manpage.nix uses it any more, so we can inline it there
instead of keeping it around as a separate generated header. doing so
will also allow us to remove caching functions needed *only for this*
Change-Id: I97ee91f1dd7140ecb69dbafd8479b82fba7981b8
